Zentangle - the art of doodling, anyone can so it! Check out this cool Seahorse zentangle This would make an awesome tattoo
A diagram concerning where to 'ink', and what to expect. It lists types of tattoo art, places, and effects on skin. This is exactly the sort of thing that inspires art. Just skin art in this case.
Photorealistic floral sleeve, Pete Zebley - No Ka Oi Tiki Tattoo, I don't really care for flower tattoos but this is beautiful
80 Awesome Examples of Full Sleeve Tattoo Ideas